Lene Hau. Lene Vestergaard Hau (born November 13, 1959 in Vejle, Denmark) is a Danish physicist. In 1999, she led a Harvard University team who, by use of a Bose-Einstein condensate, succeeded in slowing a beam of light to about 17 metres per second, and, in 2001, was able to stop a beam completely.
Zeta is the sixth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 7. It was derived from the Phoenician letter zayin. Letters that arose from zeta include the Roman Z and Cyrillic Ð.
These three cases are arranged so the value of zeta potential is the same in each case. This demonstrates that the surface charge cannot be inferred from zeta potential. It is worth emphasizing the distinction between surface potential and zeta potential. The zeta potential is the controlling parameter for particle interactions. Modifying the zeta potential requires knowledge of the potential of the surface and its chemistry. Investigation of the interaction of ions with the surface, and their effect on zeta potential is assisted by the determination of zeta potential as a function of a number of parameters.